It is known that a variable resistance element used in a resistive random access memory has two types of configurations. In one configuration (the variable resistance element), a high resistance state and a low resistance state is set by switching a polarity of a voltage to be applied thereto and the configuration is called a bipolar type variable resistance element. In the other configuration (the variable resistance element), a high resistance state and a low resistance state can be set by controlling a value and an application time of a voltage to be applied thereto without switching a polarity of an applied voltage and the configuration is called a unipolar type variable resistance element.
In a resistive random access memory using the unipolar type variable resistance elements, a memory cell array is configured such that variable resistance elements and rectifying elements such as diodes and the like are arranged between bit lines and word lines at intersecting positions of the bit lines and the word lines. Further, when the memory cell arrays are stacked three-dimensionally, a memory cell array having a large capacity can be realized without using a cell transistor and without increasing an area of the memory cell array.
In the unipolar type resistive random access memory (ReRAM), data is written to a memory cell by applying a predetermined voltage to a variable resistance element for a predetermined time. With the operation, the variable resistance element changes from a high resistance state to a low resistance state (or from the low resistance state to the high resistance state). The data write operation to the memory cell is called a set operation.
In contrast, data is erased from the memory cell by applying a voltage lower than the predetermined voltage to the resistance change element in the low resistance state for a predetermined time after data is written thereto. With the operation, the variable resistance element changes from the low resistance state to the high resistance state (or from the high resistance state to the low resistance state). The data erase operation to the memory cell is called a reset operation.
To use the resistive random access memory device as a non-volatile memory device, it is necessary that respective memory cells hold data (low resistance state or high resistance state) for a long time.
To obtain practically usable reliability of the resistive random access memory device as a non-volatile memory device (non-volatile semiconductor memory device), a management must be performed to detect a memory cell whose data retention property does not satisfy a criteria at an early stage and to determine the memory cell as a defective memory cell. However, an inefficient method of actually measuring a variation per hour of a resistance state for a long time has been used to determine the defective memory cell.